Hypo jet ampoule



Sept. 14, 1954 y R, SCHERER 2,688,968

HYPO JET AMPOULE Filed May 14, 1949 Patented Sept. 14, 1954 HYPO4 JET AMPOULE Robert Pauli Scherer, Detroit, Mich., assignor to It. P; Scherer Corporation, Detroit, Mich., a

corporation of Michigan Application May 14, 1949, SerialNo. 93,282

This invention relates to a hypodermic jet injection ampule. Injection ampules of the type to which this invention pertains are designedto contain a dosage of liquid medicament, which dosage is adapted to be ejected from the ampule by means of a hypo jet injector such as disclosed and claimed in my copending application, Serial No. 94,579, filed May 21, 1949. In said disclosure the jetfejected from the ampule passes through a minute jet orifice in the wall of the ampule in such manner and under a sufficiently high pressure to result in the necessary velocity to produce a penetrating jet that opens a channel through theskin and theunderlying tissues of` a human beingor animal for accomplishing subcutaneous injection of a liquidmedicament or' the like to a closely controlled depth Without the use of the conventional hypodermic needle. Injections of this type may be characterized as jet injections, hypo jet injections, or jet therapy, the method for which is fully disclosed and claimed in my' copending application, Serial No. 77,517, filed'Februarmy-2l, 1949. 'Jet injections represent a relatively new development in the fieldoi parenteral therapy'and are approached to some extent by the disclosures in the following Lockhartpatents: 2,322,244, June 22, 1943i; 2,322,245, June 22, 1943; 2,380,534, July 31', 1945; 2,398,544, April l6, 1946.

My jet injection ampule is rdesigned to provide for consistently successful and complete injections of the liquid contents of the ampules through' the epidermis to any desiredA subcutaneous level therebeneath.

In experimenting with jet injections* from ampules I have found that difficultyV is often encountered and Wa'stage of the liquid medicament is not infrequent particularly if quantities o f liquid in excess of about 1/5'0 cc. are to be injected. Even though the operator endeavors to stretch the'skin of the patient taut across'the point atwhich the injection is to be made, an instantaneous and clear-cut piercing of the skin by a high-pressure, high velocity penetrating jet projected from-the ampule frequently does not initially'occur and liquid is Wasted von the outer surface ofthe skin such as'would be the case if liquid were sprayed through the air towardthe skin.

With ampules having fiat areas'oi appreciable extent surrounding the ampule oriicethere was a tendency for drops of the liquid from the ampulek to collect in a pool between the skin of the patient and the end of the ampule about the orifice. There was also a tendency for this pool to increase in sizeupon the delivery kof'liquid from the ampule with the result thatv the skin was 2 Claims;` (Cl. 12S- 272) l lubricated thereby andthe end of the ampule skiddedlover theskin of the patientespecially if" the dosage was' larger than 1,50 cc. Larger dosages required larger springs` in the injectors to expel vthe addltionalliquid and this aggravated the condition. i n

Due to the high` velocity of the liquid stream discharging from the ampule orificea linear cut inthe skin of the patient marking the extent of theskid would frequently occur with resulting pain, whereas a proper jet injection is either painless or merely on the threshold of pain In order to:A avoid prohibitiveconcentration of `the liquid medicament I have found itdesirable: to inject as much as l cc. i

At the same time it is imperativethatassured accuracy as to quantity of. liquidactuallyA injected is obtained.

My improved' jet injection ampule issol shaped at its discharge end surrounding the jet orifice that when the discharge end4 is pressedI against the skin of the patient who is to receive an.injec tion, the portion-of the skin'whichV extends across the jet orifice is stretchedtaut thereover and actually bulgesy into the orifice due to subcutaneous pressure opposing the pressure of the ampule against the skin. An effective hydraulic` seal is thereby had against the edge of the jet orifice evenwhen liquid` is present around thejet orifice. Accordingly the injection is easily accomplished; there is instantaneous breakthrough of 'the skin upon impactof the high pressure penetrating jet therewith, the injection in its initial stage'as well as during the follow-through is accomplished without Wastage on the outer surface of'the 'skin and the entire dosage of liquid is properly injected to a hypoderrnic position at the desired subcuta neous level without danger of anyskidding when my improved ampule isl used in connectionV withy my hypo jet injector. i

Another important advantage of ampules pro# vided with jet orifice dischargek ends shaped' as herein set forth is that the tendency for al pool of liquidfrom the ampule tocollect betweenthe skin'and the discharge end ofthe ampule vduring injectionfis completely eliminatedl and the possible slcidding of the end o the ampule with the attendant slitting of the patients skinis also eliminated.

Still another important consideration in the. design ofan ampule is the shape of the jet disw charge orifice to reduce turbulenceof the liquid. just before it leaves the ampule and thereby se,-

cure a jet that will remain in true jet form` for maximum penetrating 'and' channel `open-v ing effect. The orifice must be carefully formed and streamlined so as to eliminate any chance for turbulence as the jet issuing therefrom has a velocity in the neighborhood of six hundred miles per hour. Any turbulence accordingly disturbs the jet so that its columnar form is not maintained and accordingly it is obviously important to streamline-the orifice and the adjacent inner surface of the ampule leading from its interior to the orice and in fact lap or polish its surface to reduce turbulence toas close to absolute minimum as possible.

With these and other objects in view, my invention consists in the construction, arrange- A ment and combination of the various parts of attained, as hereinafter more vfully set forth,-

pointed out in my claims and illustrated in the accompanying drawings wherein:

Figure 1 is a perspective view of a hypodermic jet injection ampule embodying my invention and showing one form that it may take;

Figure 2 is agreatly enlarged sectional View therethrough showing the ampule in contact with theskin of the patient, filled with medicament and having a follower backed by a plunger of the hypo 'jet injector described in my above ilrst mentioned copending application;

. Figure 3- is a more greatly enlarged sectional view of the discharge end of the ampule in contact with the skin;

z Figure 4 is similar to Figure 3 with the penetrating jet beginning to issue from the ampule and passing through the skin, and the tissues that underlie the skin; f

1 Figures 5, 6 and 'l show sectional views of modified forms of the discharge end of the jet ampule;

Figure 8 is a sectional view through another modified shape of ampule; and

i Figure 9 is a sectional view on the line 9-9 of Figure 8.

` Onv the accompanying drawing I have used the reference character A to indicate my jet injection ampule in general. It is illustrated in Figures 1 and 2 as having a cylindrical wall I0, one end being somewhat convergently restricted as at yI2 and rounded or bullet shaped as at I4, and the other end being open. The rounded end I4 may be somewhat flattened as at I5 to smooth the metal where it contacts with the skin. A shoulder I3 is provided between the cylinder I0 and the restricted part I2 to facilitate holding the muscle at 21. l`

4 ly held spaced therefrom at the time of injection.

In the ampule I disclose, the discharge end is intended to be firmly pressed against the skin of the patient at the point of injection and that portion of the ampule which surrounds the jet orifice is so shaped that the skin will be stretched taut across the orice with the edge of the ori- In Figure 2, I illustrate the skin consisting or dermis 22 beneath which the subcutaneous fat cells are illustrated at 24, the fascia at 25 and When the ampule is pressed against the epidermis it compresses the fat cells and dents the skin as illustrated with the particularly AFigure 3).

skin actually bulging into the jet orifice I6 (see The rounded or bullet shape of the ampule end results in the epidermis being progressively more tightly engaged with the ampule as the edge of the orice is approached, greatest compression being hadat the edge of the orifice and consequently this is the point of best hydraulic sealing.

,The ampule itself may be any desired shape as long as the portion thereof adjacent the orifice I6 Vis similar to a protuberance as distinguished from a more or less flat surface unless the flat surface is no larger in proportion to the orifice than illustrated in Figure 6 considering the orifice exaggerated about 2 to 1.

. In Figure 2, I illustrate liquid 26 within the ampule A which may be a liquid medicament behind which a follower 28 of Vrubber or the like is provided. This follower is adapted to be forced downwardly in the ampule A by a plunger 30 as shown in my hypo jet injector application.

The plunger 30 is propelled by suitable means such as a spring and produces relatively great hydraulic pressure on the liquid 26 to project it from the jet orifice I6 in the form of a true jet as indicated at 26a in Figure 4. The pressures involved are high, being in the thousands of pounds per square inch range and the resulting jet velocity is high, approaching the speed of sound. With the jet opening I6 being only the ampule in a hypo jet injector, the shoulder I3 engaging a shoulder in the injector.

3 The rounded end I4 has therein a jet discharge orifice I6 which is preferably between '.002" and .005" in diameter. The lower end of this oriiice has substantially parallel sides but the upper half is rounded or streamlined as indicated at I8 so that the interior surface of the jet orifice blends smoothly with the inner surface of the ampule A. The orifice I6 and the surface indicated at I8 must be accurately formed and very smooth, lapping or polishing being preferable to make the surface smooth enough to prevent any turbulence in the jet that issues from the jet orifice when the injector is operated.

` Injection ampules illustrated in the Lockhart patents above listed are provided with flat lower ends or with lower ends which are even countersunk. In most 'cases the lower ends Yof the ampules illustrated in the patents were not intendedy to be pressed against the skin of the patient during the injection but wereintentionalabout .003 in diameter however the actual pressure against the skin is relatively minute as the area is only .000009 and when the jet penetrates through the skin and into the underlying tissues as illustrated in Figure 4 it is usually scarcely noticed by the patient because of the absence of pain or at most because of the existence of only slight pain.

The ampule end may be rounded as illustrated in Figure 5 or bullet shaped as in Figure 6 which is still better from the standpoint of insuring a proper hydraulic seal to connev the jet 26a.

sothere is no leakage on the lsurface of the skin,/

andd insure that all the liquid from the ampule can be injected into the passageway opened by the initial penetrating jet.

It will be noted that the peripheral edge of the jet orifice I6 is in cross section an acute angle in Figures 5 to 8 for obtaining a more effective hydraulic sealing action right at the edge of the orifice. The end of the ampule may present a less sharp angle at this point by being flattened as in Figures 2, 3 and 4 or semi-circular in shape as shown in Figure 5 instead of bullet shaped as in Figures 6, 7 and 8 or slightly flat as at 34 in Figure 6 and as at I5 in Figure 3.

The complete injection operation takes about a seconds time and in normal injections I have vfound it best to wait about another second before removing the ampule from contact with the skin in order to insure that all the liquid goes into the jet opened channel of the tissues. Thereafter these tissues reclose the channel which was formed by the penetrating jet that acted as a means to expand the channel in opposition to the elasticity of the tissues.

Figure 7 shows a slight modification wherein a proturberance 36 is formed around the jet orifice I6 and accordingly serves as a means to effect the required hydraulic seal regardless of the shape of the remaining portion of the ampule. Figure 8 illustrates a similar protuberance 35d at a different location on the ampule. This type permits use of the ampule at places on the body where it is not possible to extend the ampule and its holder (the hypo jet injector) at right angles to the injection location. This type is particularly adaptable for dental injections as quite often it is not possible to position the injector at right angles to the point of the gum at which an injection is to be made.

The several modications illustrate possibilities for the provision of a hypodermic jet injection ampule that is successfully operable for the intended purpose. It is highly important to reduce the eiect of the pressure behind the liquid by reducing the area of the skin acted upon to substantially the minimum and of course the minimum is the area represented by only the jet opening I 6, that is, its edge. This is true even when the flat ends I5 and 34 shown in Figures 3 and 6 are provided because of the way the epidermis bulges into the orifice if the flat ends are not of much greater proportional area than illustrated. The results obtained with my ampule make the difference between a successful injection at every injection operation and injections that are sometimes unsuccessful and result in the operator not knowing how much of the injection actually took place as well as the possibility of slitting the patients skin as the result of a skid.

Ampules of the character disclosed may be made of suitable metal, or formed of plastic materials or glass if made of greater wall thickness to provide the necessary strength to resist the high pressures generated.

It will be apparent from the foregoing disclosure that when any one of my ampules is held tightly against the skin a hydraulic seal is eiected between the edge of the jet orice and the skin as to corinne the jet to only that portion of the skin that spans ther jet orice, thus minimizing the size of the puncture in the skin made by the penetrating action of the -jet and at the same time eliminating the possibility of a skid of the ampule resulting in a slit or multiple injection through the skin. Some skin is loose and flabby but with ampules shaped as illustrated good hydraulic sealing can be effected in order to provide the proper type of hydraulic seal be- 6 tween the orifice edge and the body of the patient to insure proper jet operation.

This also insures that after the penetrating jet has ceased a lower pressure follow-through jet may continue with assurance that the liquid introduced by the follow-through jet will enter the channel initially opened by the penetrating jet. The result is assured dosage quantity by a method which is reliable and by a hypo jet injector, the operation of which is relatively simple.

Some changes may be made in the construction and arrangement of the parts of my ampule Without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

claim as my invention:

1. A jet injection ampule comprising a cylinder open at one end to receive a plunger and provided at the opposite end with a cylinder closing wall having a jet orice therethrough, a protuberance extending from the outer surface of said cylinder closing wall and surrounding said jet orince, liquid in said cylinder, and a follower slidable within said cylinder to eject said liquid through said jet orice.

2. A jet injection ampule comprising an elongated cylinder open at one end to receive a plunger and provided at the opposite end with a cylinder closing wall having an axial jet orifice therethrough, a centrally located protuberance extending from the outer surface of said cylinder closing wall and surrounding said jet orice, liquid in said cylinder, a follower slidable Within said cylinder to eject said liquid through said jet orifice under high pressure to produce a penetrating jet capable of passing through the skin of a human being and penetrating subcutaneously therebeneath, said protuberance surrounding said jet orice being adapted for pressure contact with the skin so that the skin will be stretched over said orifice and bulge into it for sealing the peripheral edge of said oriilce relative to the skin.

References Cited in the file of this patent UNITED STATES PATENTS Smoot Aug. 5, 

